Organisation: Plant Tissues, Organs and System

Plant Tissues

Epidermal tissue covers the whole plant. It protects the plant and helps reduce water loss.
Palisade mesophyll tissue is located in the leaves, where majority of photosynthesis takes place.
Spongy mesophyll tissue is also found in leaves. It has air spaces to facilitate gas exchange during photosynthesis.
Xylem and phloem are transport tissues. Xylem transports water and mineral salts from the roots up to the plant, and phloem distributes sugars and amino acids between leaves and other parts of the plant.
Meristem tissue is located at the tips of roots and shoots and is responsible for plant growth.

Plant Organs

Leaves are the principal site for photosynthesis. They contain cells rich in chlorophyll and have stomata for gas exchange.
The stem provides support for the plant and helps transport substances between roots and leaves.
Roots anchor the plant in the ground, absorb water and mineral nutrients from the soil, and often store food reserves.

Plant Transport System

A plant’s transport system is comprised of xylem and phloem, found together as vascular bundles in roots, stems, and leaves.
Water and mineral nutrients enter the root hair cells by osmosis and are transported up the plant by xylem.
Sugars produced by photosynthesis in the leaf cells are transported to all parts of the plant by phloem.

Importance of Plant Organisation

The organisation in plants highlights the efficiency of division of labour and structuring in biology.
Understanding these levels of organisation illuminates how life processes like photosynthesis, growth, and nutrient transport are carried out in plants.

Transpiration

Transpiration is the loss of water from a plant, primarily through stomata in the leaves.
It’s a passive process driven by the evaporation of water from the leaf’s spongy mesophyll cells into the air spaces and then out of the leaf via the stomata.
Transpiration has a vital role in the movement of water within the plant, which includes transporting dissolved mineral nutrients and providing the water for photosynthesis.

Revising the organisation of plant tissues, organs, and systems will provide a strong foundation for understanding how these components work together to enable plants to grow and perform life-sustaining functions. It also highlights key biological phenomena, including photosynthesis and transpiration.